It seems there will be a lengthy discussion going on here. So maybe instead answering your concerns point-by-point, maybe I should go for my fundamental principles first, leaving the details in the later replies.
- Firstly, this mod is designed to be vanilla-friendly. So every setting should be "streamlined" with vanilla settings, and not removing or major modifying vanilla properties. The only exception is the removal of vanilla tank (though can be skipped in mod options), just because it is redundant with my medium tank.
- The tanks should be more powerful than player in power armour of the same level of tech (which is considered infantry).
There are much more than two, but they are not as significant and/or relevant here, so I will just skip that wall of text for now.
So yes, it actually made be headache in balancing which adhere to these principles. Things may not be optimal but still better than something get too overpowered/underpowered.
First of all, tanks should in principle have much more room for equipment, than on a power armour. I did not tune up grid size numbers, because that may make the grid screen too long/wide. So my solution is instead to create vehicle-only version of equipment, which is more powerful. It may be difficult to consider what would be "appropriate scale" for this power up. But consider what power can a tank engine give, compared to a human-carrying engine (or battery or any other equipment)? Say a typical medium tank weighs 40 tons... It would be reasonable to be 10 times or 100 times of what a super-soldier in power suit can carry! I put a "conservative" 3 (triple) in my vehicle-only variants of batteries and energy shields. Any values lower than 3 will make them too weak, not worth the 10 times material cost. Players will not bother with the vehicle-only equipment by then. So I am not going to nerf this scale.
Tanks are thought to have much more room for equipment, while in-game grid size are the same (medium tank vs power armour). It can be considered each 1×1 grid on tank "screen space" is actually a few times more in "physical space", than each 1×1 grid on power armour on "physical space". The vehicle-only equipment are already larger than the ordinary version; while the ordinary equipment is "space inefficient" when put on tanks.
This different concept is in conflict with your suggested modifications in equipment sizes. So I will not change per you said, and explain below for some cases.
The vanilla portable fusion reactor gives 46.9 kW/tile for FREE. Vehicle fuel cells consume fuel, so should obviously have much better power per tile ratings than that. I gave 2×2 the weakest value of 100 kW/tile (4×4 has higher efficiency of 125 kW/tile). If I lower these values, I wonder any players would really burn precious fuel for such little gain.
The problem you mentioned as self-powered laser turrets, is instead made by the ENORMOUS buff to personal laser defense (PLD) from the devs in 0.17! PLD was consuming 200 kJ per shot in 0.16.51. But the devs reduced this cost to 50 kJ per shot only in 0.17. The is the reason why you found PLD cheap to feed and extremely powerful.
But due to principle 1, I cannot change this value back, and do not want to force players to accept my new balance. Instead, I provided the mod option "Shot energy Personal laser defense", letting players to change the value. Please try changing this value to "200 kJ", and see if it helps the problem a bit.
(For comparison, the laser turrets consume 800 kJ per shot. I have suggested the devs to match value of PLD to laser turret for balancing. But it seems the devs and other players are too fond of the new OP PLD and "very" protective of it, not even willing to set it back to 200 kJ. Not to say higher values like 400 kJ or 800 kJ which I feel more consistent.)
For the exoskeletons, I also feel silly to allow that on vehicle grids. But due to principle 1, I cannot disable exos. And I have no good way to just exclude exos (while allowing all other "ordinary" equipment) on tank grids. So I can only leave it untouched. I can only rely on player self-discipline to not use exos on tank grids. (Thus no vehicle variant of exos, which may make it even more silly.)
I intend to let all tiers of fuel cells useful in different aspects. So I will not bump up the size of fuel cell 2×2, to let players use them on early tanks with very small grid (e.g., light tank). It already has worst fuel efficiency.